Light-emitting diodes (LEDs) own the advantages of small size, long lifetime (reaching 100 thousand hours in the normal environment), low power consumption, low heat generation, high power efficiency, short response time, high impact endurance, and high monochromaticity.
By contrast, the lamps according to the prior art (tungsten filament incandescent lamps, halogen lamps, fluorescent lamps) have the disadvantages of large size, short lifetime, high power consumption, high heat generation, low power efficiency, and pollution. Accordingly, increasingly more industries have replaced the lamps according to the prior art with LED lamps. LED lamps are extensively applied in the fields such as indicators, displays, lighting, communication, and biotechnologies, and definitely will become the mainstream products in the future. Thanks to the significant progresses in research and development, LED lamps are popularized and have certainly become the direction of development for the new era.
The LED lighting equipment has the advantage of compact size and saving space. Consequently, the market share of its application in domestic decoration is increasing. For example, LEDs are adopted as the light sources in the ceiling lamps and the bulb-type lamps according to the prior art, which are installed on walls according to uses' requirements.
A ceiling LED lamps comprises a base, a LED circuit board, and a lampshade. The base is fixed to the installation wall; the LED circuit board and the lampshade are disposed on the base. The spatial pattern, angle, brightness of the light emitted from the LED circuit board vary according to the lampshade and the design of the LED circuit board.
According to the structure and disposition of the ceiling LED lamps according to the prior art, the heat generated by the LED light source and the circuit board is conducted to the wall via the base. Alternatively, some space is reserved between the lampshade and the base for heat dissipation. Nonetheless, the heat conduction in these designs is inferior, resulting in the drawbacks of low heat dissipating efficiency and reduced lifetime in the ceiling LED lamps.
In addition, depending on the design, the circuit board of the ceiling LED lamps may be supplied by a DC or AC power source. In the respect of cleaning and maintenance, if electricity leaks in the lamp board, people might be hurt by touching. There is no protection designs in ceiling LED lamps according to the prior art for preventing the influences of electricity leaks in the lamp board on human bodies.
Moreover, in general, the lamp board of a ceiling LED lamp is fixed on the base directly. Since there is no zoom for accommodating the lamp board in the base, the space for the lamp board must occupy a certain space in the corresponding lampshade, which imposes limitations on design. That is to say, the lampshade must be designed curved. Consequently, the space utilization or aesthetic design might be affected to some extent.
Furthermore, due to their design in circuit and voltage matching, the flicker problem tends to occur in ceiling LED lamps. Flickering elicits easily physiological bad reactions such as headache, blurred vision, distraughtness, and epilepsy. To improve this situation, rectifying and filtering electronic devices should be added and connected electrically with the LED circuit board. Unfortunately, those devices occupy a certain space in the base. Besides, thermal dissipation and circuit organization are problems to be considered.